Sargent crews completed a $9.6 million CSO storage project for the City of Portland to provide 2 million gallons of wastewater storage and reduce the amount of sewage that flows into Back Cove during snowmelt and heavy rainstorms.
We installed two underground storage units which each hold 1 million gallons of sewage and stormwater, with one beneath Baxter Boulevard and the other underneath Edward Payson Park. Our teams placed 384 precast box sections using a CAT 385C excavator and a specially designed trench box with an arch on one end that could be dragged over the boxes. Each individual box measured 8’x12′ and weighed 44,000 pounds.
We also constructed two new CSO outfalls — one consisting of one 48″ RCP pipe and two 36″ RCP pipes, the other consisting of three precast boxes (10’x12’x34′, 8’x8’x32′, and 6’x7’x35′) and a 10’x12′ check valve vault. Finally, Sargent crews rebuilt 1,700 feet of Baxter Boulevard with new subbase and base gravel, storm drain, and pavement.